hw/ppc: sam460ex.c: store all GPIO lines in mal_irqs[]

hw/ppc: sam460ex.c: store all GPIO lines in mal_irqs[]

We're not storing all GPIO lines we're retrieving with
qdev_get_gpio_in() in mal_irqs[]. We're storing just the last one in the
first index:

    for (i = 0; i < ARRAY_SIZE(mal_irqs); i++) {
        mal_irqs[0] = qdev_get_gpio_in(uic[2], 3 + i);
    }
    ppc4xx_mal_init(env, 4, 16, mal_irqs);

mal_irqs is used in ppc4xx_mal_init() to assign the IRQs to MAL:

    for (i = 0; i < 4; i++) {
        mal->irqs[i] = irqs[i];
    }

Since only irqs[0] has been initialized, mal->irqs[1,2,3] are being
zeroed.

This doesn´t seem to trigger any apparent issues at this moment, but
Cedric's QOMification of the MAL device [1] is executing a
sysbus_connect_irq() that will fail if we do not store all GPIO lines
properly.

[1] https://lists.gnu.org/archive/html/qemu-devel/2022-08/msg00497.html

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: BALATON Zoltan <balaton@eik.bme.hu>
Fixes: 706e944206d7 ("hw/ppc/sam460ex: Drop use of ppcuic_init()")
Acked-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220803233204.2724202-1-danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>